Hi, i think it's possible an adaptor exists but don't know where you'd get it.
You could cut the original one off and plice/join/solder the wire for new fan in to it. You could see is can get another stock heatsink off ebay to take fan connector off if don't want to damage your own otherwise think you may need to look to electronic supplies to find the header and make your own cable.
I believe the 4pin connector on the video card is a "proper PWM" controled header, If you connect a 3pin fan to it it will run full speed all the time and not be controlled by the video card. You'd get the same effect plugging the fan in to a molex->fan adaptor or use a motherboard header (which maybe speed controlled)
I believe you could use a 4 pin PWM fan and then the card could control the speed.
You might find if you remove the plug and then the white plastic surround to leave the bare pins that you can then jam a "normal" sized fan header on to it. Will bend the pins a bit but they should be OK. Over doing it may lossen the pins but they can be re-soldered without too much trouble or special equipment. (I know cause I've been there and done it! - at least with 2/3 pin fans)
Good luck, Seb

the speed of a three pin fan is controled by the voltage supplied to the fan, but a four pin fan is controled by PWM. if you could hook the three pin fan up to the GPU fan header it would probably run at full speed all the time.

Hi, i think it's possible an adaptor exists but don't know where you'd get it.You could cut the original one off and plice/join/solder the wire for new fan in to it. You could see is can get another stock heatsink off ebay to take fan connector off if don't want to damage your own otherwise think you may need to look to electronic supplies to find the header and make your own cable.I believe the 4pin connector on the video card is a "proper PWM" controled header, If you connect a 3pin fan to it it will run full speed all the time and not be controlled by the video card. You'd get the same effect plugging the fan in to a molex->fan adaptor or use a motherboard header (which maybe speed controlled)I believe you could use a 4 pin PWM fan and then the card could control the speed.You might find if you remove the plug and then the white plastic surround to leave the bare pins that you can then jam a "normal" sized fan header on to it. Will bend the pins a bit but they should be OK. Over doing it may lossen the pins but they can be re-soldered without too much trouble or special equipment. (I know cause I've been there and done it! - at least with 2/3 pin fans)Good luck, Seb

eit412 wrote:

the speed of a three pin fan is controled by the voltage supplied to the fan, but a four pin fan is controled by PWM. if you could hook the three pin fan up to the GPU fan header it would probably run at full speed all the time.

Thanks for the info guys.
I didn't want to cut the plug on my stock heatsink for warranty purposes.
I have a Scythe Musashi on a 4870 and I wanted the card to control the fans automatically...
I can't think of any slim fans that are PWM either.. I guess it can't be done..

I m looking for the same thing, or a 4-pin MB-style to 4-pin GPU-style adapter. I can't believe they are not out there, but I've been Googling and browsing for one for two nights already and haven't seen one.

I have an Accelero S1 r2 on my Sapphire 4870 board, something I did because the board's own control lets the temp get way too high for my comfort (of course later I discovered the BIOS hack to fix this...doh). Had a 120mm all ready to go on this new heatsink, but as a self-preservation mechanism the card won't emit video unless it sees some fan RPM on that port (at least my testing with the stock heatsink indicates this).

I m looking for the same thing, or a 4-pin MB-style to 4-pin GPU-style adapter. I can't believe they are not out there, but I've been Googling and browsing for one for two nights already and haven't seen one.

I have an Accelero S1 r2 on my Sapphire 4870 board, something I did because the board's own control lets the temp get way too high for my comfort (of course later I discovered the BIOS hack to fix this...doh). Had a 120mm all ready to go on this new heatsink, but as a self-preservation mechanism the card won't emit video unless it sees some fan RPM on that port (at least my testing with the stock heatsink indicates this).

I guess I'll cut the one off the stock heatsink

I gave up looking. I had an old x850xt stock heatsink lying around so I cut the 3pin plug and made my own.

I have it on a 4870 connected to 2x 120mm Scythe Slim 1200rpm fans on a Scythe Musashi.

seems to work on Radeon 4870 boards at least. I just hacked up an adapter cable from the plug on the old heat sink to a standard 4-pin fan plug. The PWM 120mm fan I'm using spins up to max RPM when the card is powered up, then slows back down, just like the stock fan did.

Hmmm...more testing reveals that even with the proper homemade adapter cable, my aftermarket cooler/fan solution is not going to cut it. I still couldn't get the 4870 to survive a soft reset without the red temp fault light going on and video output going off. I tried running the fan full out, with only the RPM signal going to the GPU, but that didn't work, either.

I am totally at a loss how people put aftermarket coolers on these things. Maybe the problem I am seeing is only a symptom of the Sapphire board I have (lucky freakin' me). But I've spent too much time and blood pressure on it already. I ordered some thermal pad material for the RAM and am going to reinstall the sucky stock heatsink. If it cooks, it cooks.

I was going to put the original heatsink/fan back on the 4870, but the screws decided they didn't ever want to be that hot again and made a break for it. They are still hiding....

In the meantime, I did some more digging on SPCR, and basically came to the conclusion that my VRMs might not be getting cooled enough with one 120mm fan, even full blast. The stock VRM heatsink isn't very big, and the stock GPU/RAM heatsink and shroud served to duct air over it. So I put the Accelero back on and stuck it back in the case, this time with two (!) 120mm fans blowing on it, lower on the card this time so as to cover the VRMs.

Lo and behold, it's been on for two hours and no problems. It has survived a couple of soft reboots. Apparently the card was just getting too warm after power-up, but power-cycling allowed it to cool enough to come up.

I also found out that the A-C 12025 PWM fan I bought doesn't seem to put out much air. Contributing factor maybe, but I still believe you need a fan right over the top of those VRMs.

I haven't really stress-tested the thing yet, and will be looking for some better PWM fans to let the card regulate its own temps, but for now it works.

Thanks for the good info, esp. on PWM wire colors and mappings. Here's me trying to give back a little to this forum:

Can't find adapter cableI also failed to find an adapter cable (4-pin "mini PWM" plug to 4-pin standard fan PWM socket) online; I tried newegg, digikey, buy dot com, nextag, etc. I considered cutting the white plug from the stock cooling fan to solder into a custom cable, but I wanted to keep the stock cooling system intact as a backup if silent cooling didn't work.

Sound Blaster audio cable(s) to the rescueI found that a Sound Blaster (SB) internal audio cable, the kind that shipped with virtually every sound card and CD-ROM in the early/mid-1990s, has a white plug that fits the mini PWM jack. The other end of the SB cable is a black 4-pin square pin connector ("4-in-a-row"), identical to a PC speaker's internal connector that attaches to square pins on a motherboard.

Adding a 4th wireThe only catch is SB cables have only 3 wires. To get the 4th wire, steal a wire from a second SB cable: use a small flat-blade screwdriver to pry plastic clips and pop out the wire along with its square pin headers on both ends, then slide in the headers into the empty slots on the original SB cable to complete your 4-pin adapter cable. No soldering required. The only caveat is the cable has excessive length.

The white plug goes to the GPU board; the black plug fits snugly into the new PWM fan's 4-pin "extension socket" (I have an Arctic Cooling 12PWM with shared PWM). With all 4 wires connected, the video card sees fan control and sense lines, so it can control fan speed based on temperature.

Sound Blaster cable suppliers?If you don't have any SB cables lying around, you can get 2 of them shipped for $2.38 (total for both cables, including shipping) from "Monoprice dot com", part #694, "Sound Blaster/MPC-2, Audio cable". Disclaimer: I've never ordered from Monoprice, so I don't know whether they're reliable.

At least you can search other vendors for "Sound Blaster audio cable" or "MPC-2".

This little gadget can use a pwm signal to control a normal 3 pin fan. It could be useful in your case because it would give you a wider selection of fans to use. Most pwm fans end up a little too slow when controlled by the gpu header which is designed to work with very high rpm blower fans.

A 8 or 9 cm fan will be a little quieter compared to a 12cm fan at the same rpm. Since the problem in this case is cooling the vrms, a smaller fan might be a better choice, giving you more focused airflow at the same noise level.

Using the base of the stock cooler along with the accelero should also help in cooling this spot, I`m pretty sure I`ve seen someone doing it online with good results. Hopefully you can find those screws...

Finally, the easiest solution to plug a normal header on the gpu board might be removing the male header from the board and pluging the fan directly, slightly bending the pins. People replacing their psu fans usually have to do the same and I`ve done the same trick on my gpu with success (only three pins though).

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